3 research outputs found

    Comparisons of alpha-amylase inhibitors from seeds of common bean mutants extracted through three phase partitioning

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    This study compared the inhibitory activity of alpha-amylase inhibitor (alpha AI) extracted from common bean (Phaseolus vulgaris L) variety Hwachia, its nine mutants and two introduced varieties by using three-phase partitioning (TPP). A commercially prepared Phase 2 was also used to serve as a comparative reference. The optimal purification parameters for TPP were 30% saturation ammonium sulphate and pH 5.25. Considerable variations were detected in alpha AI content, total inhibitory activity and specific inhibitory activity of alpha AI purified from different common beans. Mutant SA-05 had the alpha AI inhibitory activity of 6267 units g(-1) dry seed weight, which was higher than Hwachia (5062 units g(-1) dry seed weight) and Phase 2 (3200 units g(-1) dry weight). Moreover, it had an extremely lower IC(50) (0.40 mu g) than Phase 2 (10.22 mu g). Thus, the mutant SA-05 may be used as raw material in commercial preparation of alpha AI extracts for controlling appetite and energy intake. (C) 2011 Elsevier Ltd. All rights reserved

    The Measurement and Analysis of the Instant Air Flow in the Exhaust Pipe and Intake Port for Single Cylinder engine

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    自從計算機發展以來,由於計算速度不斷增快,計算成本不斷降低,利用計算流體力學CFD軟體幫助引擎設計的例子越來越多,尤其在現代,產品週期縮短,如何應用CFD軟體來減少引擎開發的時間及實驗的花費成為各車輛製造業的重要課題。 本文利用商業計算體力學CFD軟體PHOENICS計算單缸機車引擎的排氣管及進氣道流場,為了與計算結果作驗證,本文同時利用熱線測速儀進行進氣道入口流速及排氣管膨脹室內流場的量測。為了方便排氣管膨脹室內的流場量測,本文利用壓克力仿造一軸對稱雙膨脹室排氣管,並量測及計算兩種不同轉速的流場。量測結果發現引擎排氣出口速度分佈是軸對稱,膨脹室內的流場在1750rpm轉速下量測結果對稱性較佳,3500rpm的對稱性則比較不好。計算與量測結果都顯示排氣管出口有逆流產生。 而進氣道的計算則是將實際引擎的CAD檔案輸入PHOENICS作計算區域與網格劃分並且執行流場計算,實驗則是在Flow Bench上作測試,在進氣道出入口壓力差相同的情況下,量測不同閥升程的空氣流量,實驗中同時利用熱線測速儀量測入口速度。計算結果發現雖然選用不同的設定,但算結果差異性不大。而改變兩種不同的邊界壓力設定方式,其結果有明顯差異。The computational fluid dynamics (CFD) was used in this study to investigate the flow characteristics in the engine inlet and exhaust system. The inlet flow was a steady flow simulating the flow bench test measuring the flow coefficient of inlet valve. The exhaust flow was a pulsating flow simulating engine running at constant speeds. A commercial software package PHOENICS was used in this study. In the inlet flow study, the CAD file of the engine was input to PHOENICS to generate the necessary geometric configuration of the intake system. It was found that grid size and the boundary condition at the inlet were the primary factors to affect the results of calculation. The flow rates at high valve lift were 5% lower than the measured data. However, at low vale lift, the deviations were as high as 25%. The discrepancy can be attributed to that the structured type grid system did not quite fit to the complex geometry of inlet system. A simplified exhaust pipe with two expansion chambers was used in the exhaust flow study. The velocity distributions obtained from numerical calculation were close to measured data, which were obtained with a hot wire anemometer. It was found that circulating zones emerged at the corner of the first expansion chamber, and transported down streams, and then decayed. The computing result also showed that the distribution of pressure in the exhaustion tube was one-dimensional. The turbulence intensities as well as the cyclic variations of the flow in the expansion chamber were also measured with hot wire anemometer. It was found that high turbulence flow concentrated in the second expand chamber.目錄 第一章 緒論 1.1 前言……………………………………………………………………...1 1.2 排氣流場計算…………………………………………………………...3 1.2.1 簡介………………………………………………………………3 1.2.2文獻回顧………………………………………………………….4 1.2.3 研究目的及方法…………………………………………………7 1.3 進氣流場的計算………………………………………………………...8 1.3.1 簡介………………………………………………………………8 1.3.2 文獻回顧…………………………………………………………9 1.3.3 研究目的及方法…………………………………………………11 第二章 理論模式與數值計算…………………………………………………13 2.1 排氣管流場數學模式………………………………………………….13 2.1.1理論假設………………………………………………………….14 2.1.2 排氣管流場統馭方程式…………………………………………14 2.1.3 紊流方程式………………………………………………………16 2.2 進氣道流場數學模式………………………………………………….17 2.2.1 不可壓縮流假設及數學模式……………………………………18 2.2.2 等熵可壓縮流假設及數學模式…………………………………19 2.2.3 等溫可壓縮流假設及數學模式…………………………………20 2.3 數值計算……………………………………………………………….21 2.3.1 PHOENICS簡介………………………………………………….21 2.3.2計算方法及求解程序……………………………………………..21 第三章 實驗設備……………………………………………………………….22 3.1 簡介……………………………………………………………………..22 3.2 實驗量測裝置設備……………………………………………………..22 3.2.1引擎與排氣系統…………………………………………………..23 3.2.2馬達………………………………………………………………..23 3.2.3實驗測試台………………………………………………………..23 3.2.4探針架移動平台…………………………………………………..23 3.2.5編碼器……………………………………………………………..24 3.2.6數據擷取系統……………………………………………………..24 3.2.7熱線測速儀及探針………………………………………………..25 3.2.8 風洞風速的校正及探針校正…………………………………….27 3.2.9 探針量測值與風速換算………………………………………….28 3.3 量測程序………………………………………………………………..28 第四章 排氣管流場量測結果與討論………………………………………….36 4.1 量測數據的討論………………………………………………………..36 4.1.1重複性…………………………………………………………….36 4.1.2對稱性…………………………………………………………….37 4.2 量測結果……………………………………………………………….39 4.3入口速度量測…………………………………………………………..41 4.4 膨脹室紊流場的統計分析…………………………………………….42 4.4.1整體平均法……………………………………………………….43 4.4.2循環解析法……………………………………………………….44 4.5數據統計分析…………………………………………………………..45 4.6分析結果………………………………………………………………..47 第五章 排氣管流場計算結果與討論…………………………………………85 5.1 排氣管流場條件……………………………………………………….85 5.1.1 初使條件設定……………………………………………………85 5.1.2 邊界條件設定……………………………………………………86 5.2監測點速度變化………………………………………………………..87 5.3 計算值與量測值比較………………………………………………….88 5.3.1 膨脹室中心計算與量測的比較…………………………………88 5.3.2 排氣管尾流計算與量測的比較…………………………………90 5.4 膨脹室的速度及流場………………………………………………….92 5.5 膨脹室紊流場………………………………………………………….96 5.5.1 1750rpm下膨脹室紊流場……………………………………...96 5.5.2 3500rpm下膨脹室紊流場……………………………………...98 5.5.3 壓力變化………………………………………………………….99 第六章進氣道流場計算結果與討論………………………………………...126 6.1 進氣道模型建立與計算網格劃分……………………………………126 6.1.1 進氣道模型建立………………………………………………….126 6.1.2 計算格點建立…………………………………………………….127 6.1.3 格點大小………………………………………………………….128 6.2進氣道流場邊界條件………………………………………………….128 6.2.1 入口邊界條件…………………………………………………….128 6.2.2 出口邊界條件…………………………………………………….129 6.2.3 管壁邊界條件…………………………………………………….129 6.2.4 入口流速量測…………………………………………………….130 6.3 進氣道流場計算結果…………………………………………………130 6.3.1流場分佈…………………………………………………………..131 6.3.2流量係數…………………………………………………………..135 6.3.3氣缸內翻滾流……………………………………………………..139 6.4不同設定條件的影響………………………………………………….139 6.4.1模式的比較………………………………………………………..140 6.4.2 格點的比較……………………………………………………….142 6.4.3不同邊界設定對計算的影響……………………………………..144 第七章 結論與未來研究方向………………………………………………….166 參考文獻………………………………………………………………………...16

    Genetic diversity in NaN3-induced common bean mutants and commercial varieties detected by AFLP

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    The analysis of Amplified Fragment Length Polymorphism (AFLP) was used to estimate genetic diversity in common bean (Phaseolus vulgaris L.) variety Hwachia and in 34 NaN3-induced mutants and 11 commercial varieties introduced from China. Eight primer combinations generated 516 DNA fragments of the tested mutants and introduced varieties, of which 448 fragments were polymorphic. The calculated Jaccard similarity coefficients based on AFLP data ranged from 0.47 to 0.84. The molecular profiles obtained from eight AFLP primer pairs indicated a high genetic diversity among Hwachia, NaN3-induced mutants and introduced varieties. The extent of genetic variation was slightly higher between Hwachia and NaN3-induced mutants than between Hwachia and introduced commercial varieties. These results, supported by cluster analysis, suggest that NaN3-induced mutagenesis effectively broadens the genetic diversity of common bean varieties. Some of the produced mutants could be useful as sources of variation to develop new improved common bean varieties
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